I’m like 2 hours away from Berrien Springs and I’ve never heard of this.
I think that just means you haven’t found the Christmas Pickle yet…
Actually I have two elderly German friends who do this tradition.
I fail to find any solid sources for this supposed tradition, apart from a questionable wiki article with misleading or broken citations. The wiki article was created in 2004 with a link to a personal webpage from 2002 on how to create a Christmas pickle graphic in PaintShop Pro.